a question about Maxwell equation

Taken from http://en.wikipedia.org/wiki/Del_operator.

In other words, the divergence of J is a measure of how much J change
en la direction given by J itself. Or the solution is the same and there is
no ambiguity.

But i think the ambiguity here is between (a) & (b)

(a) Physically, change of coordinate system should NOT change how fast the charge accumulates in a point.
(b) Mathematically, change of coordinate system does seem to change how fast the charge accumulates in a point.

Hi Adun

Being x'y'z' is the rotated system it holds:

x'= -x and (x' versor) = -(x versor)

So you get J =(x' versor) x'

and d(rho)/dt = -5 is not changed by the rotation.

thanks lagrange, i just realized my math flaw when i am taking a shower:)
hail to the maxwell equations